PROVINCETOWN — The first year that artist Judith Motzkin raised her hand to participate in the "Appearances" Green Arts Festival in Provincetown, she didn't know what she was getting into.

She carefully installed her ceramic posts and recycled ceramic pieces, titled "Dis/Appear," in a tidal area near the Province­town Inn, not realizing that they might be covered or radically changed over the course of several days. At times, in fact, Motzkin said, the posts disappeared underwater.

"If you stayed long enough, the pieces would appear," said Motzkin, who lives in Wellfleet and Cambridge.

The idea behind the event, now in its third year, is to celebrate the environment, highlight its fragility and beauty and to explore its connection with art. The festival was founded by Dorothy Palanza, an artist and a trustee of the Provincetown Conservation Trust.

This year's event is planned for April 19-28 and the call for art submissions ends March 2. The timing coincides with spring and the warming of the Earth, the budding of plant life and the return of migratory birds and sea animals such as humpback and North Atlantic right whales.

About 100 artists contributed to the event last year from as far away as New Zealand. About 60 percent of the displays and events were outdoors last year, Palanza said. Local galleries and organizations will offer indoor space again this year, she said.

The trust is hoping to use the Dunes' Edge Campground on Route 6 as a setting. However, the sale of the private acreage to a nonprofit land management group for public use is still in the works and the timing of the sale could affect the extent of the festival's use, campground owner Miriam Collinson said.

The Provincetown Film Society will partner with the festival this year, too, to show films about fishing, climate change, garbage, whale entanglement, along with the classic "Moby Dick." Provincetown International Film Festival Executive Director Gabrielle Hanna said.

Motzkin said she doesn't know what will happen with her submission this year. "On a personal and artistic level, any opportunity to do something out of the norm of what I can do is worthwhile," she said.